Torque and Speed for DC motor

  Torque is inversely proportional to the speed of the output shaft. In other words, there is a tradeoff between how much torque a motor delivers, and how fast the output shaft spins. Motor characteristics are frequently given as two
points on this graph:

•   The stall torque, represents the point on the graph at which the torque is a maximum, but the shaft is

not rotating.

•   The no load speed, is the maximum output speed of the motor (when no torque is applied to the output shaft).

  The motor load determines the final operating point on the torque curve. As illustrated in the figure below,
when a motor is connected to drive a load, the interaction of torque demanded by the load and the torque
produced by the motor determines the point of operation.